<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>findKeys</title>
</head>

<body>
    <div>打开浏览器控制台查看结果</div>
    <script>
        const findKeys = (obj, val) => Object.keys(obj).filter(key => obj[key] === val);
        const ages = {
            Leo: 20,
            Zoey: 21,
            Jane: 20
        };
        console.log(findKeys(ages, 20));
    </script>
</body>

</html>